1. Field of the Invention
This invention relates to a method for highly drying an ammonia stream, more particularly, it relates to a method for drying an ammonia stream characterized by passing the ammonia stream through liquified ammonia in which sodium metal is dissolved and which is maintained at the boiling point.
2. Description of the Prior Art
There are two typical conventional methods for drying an ammonia gas.
One is the method in which an alkaline drying agent is employed. Whereas this conventional method has the advantage that a larger quantity of ammonia can be continuously dried, it has the defect that approximately 4 ppm of moisture can not be removed from the ammonia gas, even if the strongest drying agent, CaO, is employed under the most effective conditions.
The other typical one is characterized by liquifying the ammonia gas to form a liquid ammonia and dissolving sodium metal therein to remove the moisture. When this conventional method is actually carried out, the liquified ammonia is heated to evaporate. This conventional type of method has been known as the most effective drying method. However, this conventional method has been used only on a laboratory scale, because it can not be carried out except inside a sealed glass container.
As explained above, the conventional methods for drying an ammonia stream suffer from defects, and therefore, there has long been a great need for improving the conventional methods, thereby developing a new method for ensuring effective and efficient removal of the moisture from the ammonia stream.